{G. B. Lal; Lancaster Press, Inc. [O. J. Smith, Jr.]; Hugo Landi; R. J. Lang; Sir Joseph Larmor; Jennie B. Lasby; Latvia University Astronomical Observatory, Riga [S. Slaucitajs]; G. Lecointe; H. Lehmann; Lemcke & Buechner; George H. Lepper; Sophia H. Levy; Lick Observatory; Bernhard Liebisch}
{Agnes Leek; Sophia Levy; Mary J. Lilly; Edna Lockridge; Gladys L. Long; Merl McClees; Florence MacCreadie; Marjorie Butterick Macgowgan; Christine McMartin; Maud W. Makemson; Isabel E. Martin; Beatrice W. Mayberry; Mary Maynard; Addie Miller; Mabel M. Miller; Anna Molander; Mrs. George S. Monk}
{--Kammerlingh-Onnes; "Kapteyn Cottage"; B. Karpov; Katherine P. Kaster; Kasan University Astronomical Observatory; Katherine P. [Mrs. H. B.] Kaster; J. Kater; Heinrich Kayser; C. H. Kelley; Hugh J. Kelly; Roy J. Kennedy; Norton A. Kent; Frederick P. Keppel; M. de Kerolyr; Keystone View Co. of New York, Inc. [F. Lorenz]}
{F. G. Hagemann; H. M. Hall; J. Halm; Hamburg Seewarte; Richard Hamer; W. J. Hanna; E. Hartwig; Georg Hartwig; Harvard College Observatory; Herbert Harvey; Margaret Harwood; W. Hassenstein}
{Pacific Electric Railway Co. [incl to/from GEH]; Pacific Geographic Society [Humphrey Read]; Pan American Scientific COngress [José J. Bravo]; Paris Observatory; Const. Parvule; J. Newton Parker; Sir Charles Parsons; Pasadena Association; Pasadena High School and Junior College [Ida E. Hawes]; Pasadena Vocation Bureau [Marion de Paar]; A. W. Pawlow; Fred Pearson; Peckham Bros.; George B. Pegram; Walter M. Pegram; Peking Central Observatory; G. Edward Pendray}
{A. O. Tait; Tashkent Astronomical Observatory; A. Tass; Taylor and Francis; Taylor Instrument Cos.; Taylor, Taylor, & Hobson, Ltd.; Robert J. Teall; Jan Teders; B. G. Teubner; A. David Thackeray; O. Thomas; W. Irwin Thompson; --Thorndike; E. R. Thorwarth}
{Felix M. Perez [Sanchez]; T. P. Perkins; Nicolas Perrakis; C. D. Perrine; Max Petersen; John E. Pfeiffer; Philadelphia Inquirer [John Miller]; "Pinacyanol" [advert from Lucius & Brüning Farbwerke]; Harry Hemley Plaskett; Poggendorff's Biographisch-Literarisches Handwörterbuch; Popular Astronomy; Popular Science Monthly [Sumner Blossom]; M. A. Porcabeuf; J. G. Porter; Potsdam Astrophysical Observatory [H. von Klüber; E. F. Trondlich]; Poulkovo Observatory; N. R. Powley; Poznan Observatory [Joseph Witkowski]; Irwin G. Priest; Henry S. [& Mrs.] Pritchett; S. Procopin; W. S. Prosser; Herbert Putnam; G. P. Putnam's Sons; W. F. Quarrie & Co. [S. E. Farquhar]}
